: This proposal seeks to advance our understanding of the role of psychosocial and environmental health risk factors as well as medical care in understanding the large socioeconomic and racial/ethnic disparities in health and the way health changes with age in our society. It does so by proposing to extend to four waves and 15 years of follow-up an ongoing prospective study (known as Americans' Changing Lives) of a nationally representative sample of 3,617 adults aged 25 and over in the coterminous United States, who were first interviewed in 1986, with reinterviews of about 83 percent of the surviving members of the original sample already completed in 1989 and 1994, along with ongoing mortality ascertainment on the full original 1986 sample. A proposed fourth wave would be collected on about 83 percent of the surviving sample (estimated respondents - 2,300 of about 2,800 survivors) in 2001, primarily by telephone and in person as necessary, with mortality ascertainment continuing indefinitely and the hope and intent of reinterviewing surviving respondents again about 20-22.5 years after the baseline interview. The ongoing ACL study has generated a large body of publications both by staff of the ACL project and users of the public use data sets for the first two waves (with the third wave to be archived for public use by the end of 1999). ACL analyses and publications have illuminated to the role of a broad range of psychosocial factors, ranging from health behaviors through stress and adaptive resources to productive activities, in predicting health, changes in health and mortality, and in mediating or explaining socioeconomic differences in health. It has also played a major role in understanding the nature, causes, and consequences of paid and unpaid productive activities over the lifecourse. The proposed continuation and extension of the ACL project will address a number of aims: (1) continuing and enhancing ongoing analysis by extending prospective follow-up to 15 years, allowing for better analysis of- (a) time- varying covariates, (b) the impact of changes in risk factors on changes in health, and (c) potential reciprocal relationships between and among SES, psychosocial risk factors and health; (2) enhancing and improving the measurement of a number of variables already being considered in ongoing analysis, including SES (e.g., improving assessment of wealth), productive activities, religious beliefs and behaviors, and personality or dispositional factors (e.g., hostility, optimism, hopelessness, and John Henryism); (3) adding new measures to ACL 4 or (via archival data) to all waves of data for both medical care and exposures in physical and social environments; and (4) to undertake more focused analysis of racial/ethnic differences in health and explanations of them.